Rotatable adjustment knobs or control knobs are commonly utilized to adjust settings of optical, mechanical, and electrical devices. Riflescopes and similar weapon aiming devices commonly include a pair of orthogonally mounted rotatable adjustment knobs, also known as turret knobs or simply turrets, which are used for adjusting elevation and windage settings affecting the respective vertical and horizontal aim of the riflescope, and thus of the weapon to which the riflescope is attached. Rotating adjustment knobs are also commonly used on riflescopes and other optical devices for adjusting focus, reticle illumination intensity, display settings, display illumination, and other settings of the device. Rotating adjustment knobs are also used on various other optical, electronic, and mechanical devices, such as spotting scopes, binoculars, microscopes, stereos and radios, appliances, automobile controls, and measurement instruments, for example.
In some applications, it is advantageous for an adjustment knob to automatically lock in place to prevent inadvertent adjustment. U.S. Pat. No. 8,006,429, issued Aug. 30, 2011, describes various locking turret knobs for riflescopes, some of which are normally locked, but may be unlocked by applying a releasing force to the knob or a component thereof, then rotating the knob to make an adjustment. In some embodiments described in the '429 patent, when the manual force is removed a spring or other biasing device of the knob automatically returns the locking mechanism to its normally locked state, preventing inadvertent rotation of the adjustment knob, for example during transit or other handling.
Patent Application Publication No. US 2011/0100152 A1 describes an auto-locking adjustment mechanism including a pair of buttons on opposite sides that are manually depressed with a pinching action to release the locking mechanism and allow the knob to be rotated for adjustment of a setting of a riflescope or other device. When force is released from the buttons, the device automatically locks. Hence, the adjustment mechanism is sometimes referred to as a pinch-and-turn adjustment knob or a pinch/turn knob. The buttons are carried by a knob body that is installed over and frictionally secured to a threaded spindle of the device by a pair of set screws. The knob carries an indicator ring marked to provide a visual indication of the rotational position of the knob relative to the riflescope. The zero position of the knob can be adjusted relative to the spindle by loosening the set screws, rotating the knob until a zero marking on the indicator ring is aligned as desired relative to the riflescope main tube, then re-tightening the set screws. Each of the buttons carries an actuator shaft that extends radially through a bore in the side of the knob body and operatively engages a linkage within the mechanism that is driven in an axial direction when the buttons are depressed to release the locking mechanism, allowing the knob body and spindle to be rotated together to drive a threaded adjustment screw plunger or another type of adjustment device.
The present inventor has recognized a need for an improved auto-locking pinch/turn adjustment knob.